Increased Peripheral Blood Plasma Amyloid and Tau Concentrations Associated with MR Elastography Measures of Brain Stiffness

Motivation: Alzheimer's Disease (AD) diagnosis relies on amyloid-b and tau pathology accumulation and cognitive impairment, but early identification of pathological buildup could introduce early intervention opportunities. Goal(s): We aim to use MR elastography (MRE) to reveal associations between amyloid and tau levels in blood plasma and mechanical measurements of tissue damage. Approach: MRE and a blood draw were completed to quantify brain mechanics and plasma concentrations of biomarkers in middle-aged and older adults. Results: Increased blood-based biomarker concentration is associated with decreased hippocampal and entorhinal cortex stiffness in agreement with previous literature describing that tau accumulation begins in these regions disrupting local tissue mechanics. Impact: This study shows the first evidence that increased plasma concentrations of amyloid and tau biomarkers are associated with decreased stiffness in regions associated with early AD progression. MR elastography is sensitive to regional damage caused by tau and amyloid accumulation.